package alg20241021;

public class Text2 {
    public static void main(String[] args) {

    }
    public int waysToStep(int n) {
        //1创建dp表\
        //2初始化
        //3填表
        //4返回值
        if(n == 1) return 1;
        if(n == 2) return 2;
        if(n == 3) return 4;
        int[] dp = new int[n+1];
        dp[1]=1;
        dp[2]=2;
        dp[3]=4;
        for (int i = 4; i <= n; i++) {
            dp[i] = dp[i-1] + dp[i-2] + dp[i-3];
        }
        return dp[n];
    }
}
